A memory card (semiconductor memory card) having a NAND-type flash memory or the like is being downsized and provided with high capacity rapidly. For realization of a downsized memory card, semiconductor chips such as a memory chip and a controller chip are mounted in a stacked form on a wiring board. Besides, the memory chips have come to be often stacked into multiple layers on the wiring board. The electrode pads of the semiconductor chips are electrically connected to the connection pads of the wiring board through metal wires (bonding wires).
To realize a memory card with high capacity, provision of the memory chip itself with higher integration and higher capacity based on it is being conducted in addition to the improvement of the stacked structure of the semiconductor chips such as a memory chip and a controller chip on the wiring board. The outer shape of the memory chip tends to become large when it is provided with high capacity. The outer size of the memory card is specified by SD™ standard or the like. In addition, the outer circumference of the memory card is provided with a cutout portion to indicate the forward or backward direction and the front or rear surface direction of the card when it is fitted into a card slot (JP-A 2007-293800 (KOKAI)).
In a case where a large memory chip is mounted on a wiring board for the memory card, the connection between the wiring board and the memory chips might become difficult. It becomes a factor of restricting the number and size of the memory chips mountable on the wiring board. To perform wire bonding of plural memory chips, the plural memory chips are stacked in a step-like shape to expose the electrode pads arranged along their short sides (JP-A 2005-302871 (KOKAI)).
When the memory chips which have the electrode pads arranged along the short sides are stacked into a step-like shape, their length in the stepped direction becomes long with the increase in the number of stacked memory chips, and an occupied area of the semiconductor chips relative to the wiring board increases. It becomes a factor of restricting the number of memory chips mountable on the wiring board to disturb the provision of high capacity which is demanded for the memory card. In addition, the memory chip having a single-short-side pad structure might not be able to comply with an increase of the number of electrodes on the basis of the provision of high integration and high sophistication.